Alarm device



March 13, 1945.

A. J. sTocK E11/x1. 2,371,272

ALARM DEVICE Filed Dec. 12, 1941 4 Sheets-Sheet l March 13, 1945. A. J. STOCK ETAI- ALARM DEVICE Filed Dec. v12, 10941 4 Sheets-Sheet 2 Marc i3, 194% A. J. STOCK y-:TAL 2,373,272

ALARM DEVICE Filed Dec. l2, 1941 4 Sheets-Sheet 3 LA TCH March 13, 1945.

A. J. STOCK ET AL v ALARM DEVICE Filed Dec. 12, 1941 4 Sheets-Sheet 4 3mm/tod Patented Mar. 13, 1945 l Arthur J. Stock and Nathaniel Brewer, Cleveland, Ohio; said Brewer assigner to said Stock, doing business` as Stock Engineering Company, Cleveland, Ohio vAppliance December 12, 1941,- seriaiNo. 422,758

` 1o claims. rc1. rml-311) This invention relates to systemsfor feeding aggregate materials such as coal, coke or the like.,

and more particularly to an alarm device for such systems which will give an lalarm if a stoppage occurs and thus aid in preventing interruptions in the feeding of aggregate materials through such systems. f i

The problem which this invention is designed to solve arises "particularly in connection with the systems used toy feed coal or coke to the ilres` under the boilers of a power' plant. Insuch installations, coal or coke is commonly fed from an overhead bunker-,through a weighing device, to a pulverizer-feedei1 otr-.Stoker of a power plant. If a stoppage occurs at any place in this system,

the boiler ceases to be `supplied With coal and it v is highly desirable that this dangerous condition be remedied at the earliestv'possible moment. In

` present practice, wet, fine coal must often .be

burned under boilers and this Wet, ne coal occasionally refuses to flow properly and causes stoppages in the system which gerous if not corrected'.

Numerous alarm devices have been proposed in the past but none have been positive or sure quickly become danfrom the bunker onto a belt conveyor which feeds it to a Weighing hopper carried on scales. From this hopper the coal is discharged into a chute which directs it to a pulverizer-feeder or Stoker.

`The operation ofthe belt conveyor is controlled by the scales which carry the weighing hopper so that the belt conveyor continues to operate untilthe `weighing hopper balances the scales, at

which time the belt conveyor stops until the weighing hopper has discharged and is ready to receive another load of coal.

The present invention preferably comprises two units, one operatedby the belt conveyor and weighing mechanism, and the other operated by the stoker o1 pulverizer-feeder and weighing mechanism. Each unit consists of a driven means, driven in one case by the belt conveyor and in the other case by the pulverizer-feeder or Stoker, and a re-setting device, operated, in either case,"by the weighing mechanism. Each unit also includes a relay or switch mechanism .which is operated by the driven means after it n has been driven to a predetermined extent, proenough in their operation. Many such devices f are readily clogged by coal and hence fail in open!v ation and othersare capable only of locating` the system.

Accordingly, the present invention comprises a mechanism that operates in conjunction withy quick, dependable and accurate indication of i stoppages in certain relatively small sections of Whether or not coalv is flowing in the system, and 1 if not, where the stoppage has occurred. 1

Most coal feed systems consist of abunker from,4

which coal passes to a weighing mechanism and either a pulverizer-feeder or a stoker to which the coal passes from the weighing mechanism. One such weighingmechanism is described and illustrated in an applicationfor letters Patent of the United States filed by Arthur J. Stock on vidingit has not sooner been reset by the action of the weighing mechanism.

Thus, as the belt conveyor operates, or as the stoker mechanism or pulverizer-feeder operates, it drives the driven means toward a point Where it will'operate the relay or switch mechanism. Howeverfif* coal or other material vis flowing through the system in a normal manner, the Weighing mechanism will operate before the driven means reaches a point Where it will actuate the relay or switchmechanism and the operation ofthe Weighing mechanism will actuate the re-set device which will restart the cycle. This continues as long as the system is in normal operation,` "but if for any reason coal ceases to flowA in the system, the driven means will then August 26, 1940, and assigned the Serial Number of 354,148. The alarm system of the present invention is particularly well adapted for use with this Weighing device and hence will be `described as it is used therewith. However, it is tobe un?,V

derstood that the alarm device ofthe present invention may Weighing device. 4

It so happens that'in theweighing mechanism of the aforementionedapplication, coal passes lbe 'used-with any other similarr be operated to a point where it will actuate the switch or relay mechanism, which in turn will operate an indicator or signal, thus informing the operator ofthe stoppage of the system.

' If the stoppage occurs above the Weighing hopper, the belt conveyor will operate for a longer period than usual in an attempt to supply a load of coal to the weighing hopper and this fact will cause operation of the signal of the alarm unit drivenby the belt conveyor. On the other' hand, `if the coal vstoppage occurs between the weighing hopper and the pulverizer-feeder or Stoker, then the coal will pile up'in the chute under the Weighing hopper and prevent operation of the weighing mechanism, thus causing the pulverizer-feeder or stoker to voperate for an unusually long period between operations of the weighing mechanism, which fact will be indicated by the alarm unit driven by the pulverizer-feeder or Stoker. vice is operated electrically in such a way that the However, if the coal stoppage occurs above the electric motor II operates the belt conveyor I6 weighing mechanism coal will sooncease to be 5 until such time as the weighing hopper I8 is lled delivered from the Weighing mechanism to the to a point where it balances the beams I9 of the pulverizer-feeder onstoker and hencethe alarm scalespftthe weighing mechanism at which time covering this :parlaofy theysystem will alSQ-Qperate. s current; tof the electrical emptor I'I is-interrupted To prevent this, a second. mercury switch may so that the motor stops; the gate 20'is released so be positioned alongside of the, rst in the upper l10 that it opens and allows the coal to discharge alarm, and arranged so that upon actuation of therefrom; the gate 20 then closes, the motor I'I the alarm this second switch will break the cir-L yis:121goin.;energized and the cycle is repeatedcuit of the lower alarm, thuspreyenting its op-I Upon reference to Figure 4 it will be seen that eration, The lower alarm cansthen begsettohave motor I'I-, 1;which-,-asillustrated, is of the three a slightly longer period before `itoperatesl ,sothatlia.Phasestypa is supplied with current through lines in case of a stoppage above the coal`weighing 55;'56and S'Iwhichlead into and through switch mechanism the upper alarm will have a chance to box 58. Within switch box 58 is a motor switch render the lower alarm inoperative before-i1,opl 59 7operatedtbya solenoid 6U. Conductors 6I, 62, erates at all. However, even though the loweny 63 and Las-well as manual master switch 65 and alarm does operate simultaneously with or a little 20 4mercury switches 65 and 6'! control the flow of before theuppergalarmfitwillxjbe cut-oft. byathmfcunlent;to',fsolerloidc. rTT1IlS..-;Whnvm0'0r l1 iS operation `of :the upper alarms If the stoppage occurs between-.the k,pulverizerfx feederor. stokerandthe weighing mechanism; coali l and arranged to discharge through a gate 20 at the bottom thereof. The automatic weighing deprevent the Vclosing of` thegate1at-.the-bottompof; the hopper.,l Thus;A the; .beltsxrconveyon will; be stopped f before the alphen .alarm is operated but ,-1 willsimply; remain linizthatostate until the .lower beam I 9 is Iin horizontaL- positionsas Iis the case system again in proper operation-.3.

It.wi11 ,be-,apparent-:that eithenofuthetwo alarm untsnaybe; used'.Separatelyffromzthe other, and

August, 26;` 1 940 and -hereinbeforementioned,mer-v invention ,-may, be i1s ed ingconnection with, ;sys 35 tems;r employing =0ther ;weighing devices of this. same general. character.

Anunderstanding `ofthe. more detailed.,- features 0f i this inventioirandof. .tslnumerous advantages?. maybe. hadbyre .StillolyaofI thezappendedgrawings 5,40 deenergigedsandzmoton I 'nto stop..

61;wilLbe .effective andthe ycircuit containing Vit andthe 4followingieletailed; description thereof;

Figurer-l is-.a semiediagrammatic.illustration ing..y side; elevation; fand; wthcertain :parts-fcutaway-.toit show the mechanism morei-iclearly,s0f;1the,prin-z.- oiples .of this invention ,appliedsto a coal;` supply systemsi., f

byA solenoid 69, E, Since; ascanbe seen-in Figure 4,

Figure -2 isa frontgelevationfpartly insectionxof 5i theppllngofwitch. ESI-willresultinthe release one; ofthe; .units l,employedgaccondingzsto: ithis; in-

off, lathz- B-,asf .Well astthe. ,stopping-oi 1.1101501'v l 7- ventmmthe .coverbavingibeenfremoved to-exposegfom''hus the hopper gate 20 will open under the in-v the workingpartsgg uenceofthe, weight of.,the material contained Figures is an ena eier/ationerithefsame.units; therein. The epenins of@ gateVA 'flhwllll4 alsoy Cause Showing' Vcoyelijrng@intheilu-liu,illfllplgce Secr. Switch 66, pivotauymollnted at tOOpeITSO that tioned to expose the. interior` partsa Figure-4 is a wiring;diagramrshowingtheyconf;-55 trois.for-the motorassociatedfwithithe weighing.` "quantity:Qf.:agg1'egate.under gate A2li/is such as to m9ha1lSm andi;

Figure 5 isa wiringrdiagram showing the .manner` in whichthe alarmfunits' are connected;` fon-f.; operation,

clr,use ,afterl dischargingandA Somercury switch 66 will, be V.biased to r circuit l closing position.. Simi:

As iuustratedlinrigure ,1, eoal, coke orfothenlo"larlatheloss.Of-theLWeeht0rmr1y,in hopper-18x aggregate material passes;fromlbunkerIlalintoza tionand so .,bias sw1tch 6l.to. closed position.

an automatic Weighing device'l 2; of; tliednlev der-.- scribed inthe above-mentionedapplication of into a chute I3 whichconveysit toa pulyerizerf l feeder I4. Fromthisffeederfitpassesthrough a chute I5.into theiurnace.V

The automatic weighing deviceJZ will-not be, described here .indetail lsince it is `ralready they-0m subject matter of anotherfpatent application, buh: 'dlythe.beltCOnYeyor Iand itsreset mechait may be stated generallyfthatit comprisesfa beltf conveyor, I 5. driveny byan, electrical motor .I 1lv so;as ;A to feed coalorthe likeffromthe bunkenl I intOla more fullydescribed..

The. upperalarm .unitwhichis Ashown in greatendetail 'in FiguresZ and 3 lsconnected-sothat unitis .re-set eachtimethemotor is ,started,see

to :,bezstarted tdriveuconveyor 1l l`r so vthat aggro- 'Y gatefmaterial maybe: -fedv vfrom bunker` I I tohop-L perflprnanual yswitchf-Iiifis moved to,r closedposif willpilefup.underthepweighing;mechanism and ;25 tiomg-Thiswili close,thercuittosolenoid Iif a switches I itand Haare; alsoclosed whichv will 'be the case if the hopper gate 2U is closedand the v cury-fswitch llil-is fmounted-inswh la way thatit v is normallybiased to circuit yoloeningposition but, that alarmunitsembpdyingthe;principlesofthis, 'is heldinfcircuitfclosing position by beams I9` ,whenxthey are horizontal. When Athe hopper. I8 fills, :.howevenfand :thefleft end pibeams I9, 4as viewedinfEgurefl, rises, Athe normal bias of switch will;be,opened.;` ,This will Lcausesolerioid,6I] to be ,Y

Upon .,referencefto-,Figure l it will beseen that, hopper gate 20 isrheldvclosed-byfa latch `68 which, by means not shown, is held `in latching position I solenoid- .S8-.is controlled .bm-switchlSB.' it is evident` the motorcircuit maynotbe;reestablished in the Veverrta stoppage exlststbelow gate .20,.so that the v impede/its., normal. .closing by counterweight action. In thaabsence,@impediment gate 20l will l Under,.these,conditionsthecircuit tomotor. I 1. will Arthur J. Stock, and ,from this-,weighing ,devices -,besmadetaS-WellasthatU0latchS01en0df59far1d:i D resei'flin.-solerloids.T 43 `iand.43a. ,to behereinafter.

its drivenmeans .isdriven by the motorv I1that I nismiis ,operated from the .electrical ,circuit that ,y operates the motor I1 in such a mannerthatsthe.

whenhoppen IB is empty.;` Asi ismorefully-de-y f alarmhas operatedt@the` stoppageleared andthe: emmscribedfin application Serial Numberali; filedl dangers l to be Vdriven from the pulverizer-feeder- I4 but both of the alarm units will cause' a signal'to be given. Y

The motor for or manner of operating pulverizer feeder |4 has not been shown since any conventional arrangement may be used. It will be understood, however, thatin a normal installation pulverizer feeder I4 will operate continuously and entirely independently of motor |1 or the conveyor driven thereby.

Each of the alarm units specifically comprises,

verizer-feeder or stoker by appropriate bolts 2E.y

Each unit is driven by a shaft 21 which extends from the mechanism lfrom which the unit is to fbe driven into the unit itself and carries within the unit a worm 28. The shaft is connected to l any appropriate driven shaft in the `device from which it is driven, for example in the weighing mechanism to one of the shafts in the gearing between the electrical motor I1 and the belt conveyor I6, and'` in the pulverizer-feeder I4 to the main-drive shaft.

In each alarm unitthere is a worm-wheel'29,

which meshes with the worm 28 except during' operation of the resetting device. i The worm wheel is carried rotatably on a pivoted shaft'30,

pivoted at a point 3|, which is remote from the worm-wheel, in a sub-frame 32, which is attached to the main frame 23, by a pair of bolts 33.r The weight of the pivoted shaft and the parts carried by it is partially counterbalanced by the action of a coil spring'34 connected between it and the sub-frame.` i f 'Mounted upon the pivoted shaft is a smallv hinged frame 35, which carries a mercury switch 36 Aand is so constructed that the mercury switch willnormally remain in the off position. The hinged frame, however, carries an upstanding arm 31 which passes close to one of the faces of the worm-wheel 29 and the worm-wheel 29 `has a projecting pin 38 upon that face `so ar-` ranged that if the worm-wheel 29 is revolved to a suiicient extent, the projecting pin 38 will engage the upstanding arm 31 on the hinged frame and tilt the movable part of the hinged frame, which in turn tilts the mercury switch 36 so as otherwiseV continue to rotate and break the switch mechanism. Y V

The resetting mechanism consists of an arm 4I attached to the end of vpivoted shaft 30, re-

T'mo'te from the pivot 3|, a dash-pot assembly42 connected to the end of the arm 4| and a solenoid 43 which operates through the dash-pot to lift the pivoted armV 3|), thus disengaging the worm wheel 29 from the worm 28. The worm-wheel 29 is then caused to rotate back to its original'` position by a coil spring 44 which is connected between the arm 4| which is xed to the end of thelpivoted shaft 30 and the worm-wheel 29, in such a manner as to rotate the worm-wheel back to starting position.

In its starting position the pin 38 contacts a Aslider 45 which is carried on an upstanding lug 46' on-the main frame 23 and held in position by thumb screw 41. The position of this slider may be adjusted to adjust the starting position of the worm-wheel.

There is also a second projecting pin 48 on the other side of worm-wheel 29, which projecting pin is positioned at an approximately 90 angle' around the worm-wheel from the rst pin. There is further, a second upstanding lug 49 on the main frame, on the other side of the worm-wheel from the lug 46, and the slider 45 may be transferred to this lug so as to cooperate instead with the second `pin on the worm-wheel, thus making possible another range of starting positions for the worm-wheel.

The main body of the dash-pot arrangement 42 is" connected directly to the arm 4| of the pivoted shaft 30 and the plunger 5l] is connected to the armature 5| of the solenoid 43. Solenoid 43 is connected to conductors 56 and 51 leading to motor I1 so that solenoid 43 is energized only when the circuit to motor I1 is closed. The plunger 50 consists of the usual type of plunger element except thatopenings 52v are made through the plunger and a washer 53 placed around the shaft of the plunger and laid on top of the openings 52. Thus when the plunger-moves upward, the openings a're closed by the washer so that the upward movement of the solenoid armature lifts the whole assembly and with it the end of the pivoted shaft and the worm-wheel 29. The dash-pot, shaft and gear thereafter returnl slowly to their original po- 50'sitions as leakage past the plunger takes place.

to actuate it. The terminals of the switch are sufcient extent so that the projecting pin 38 engages the upstanding arm 31 on the hinged frame and tilts the movable part and with it`the mercuryswitch 36, the worm wheel 29 will then reach a position where the part 29a from which the teeth have been stripped, will be opposite the worm 29, so that no further movement will take p1ace-.- This eifectually prevents the continued rotation of the worm wheel 29,V which would However, upon release of the armature 5| of the solenoid, when the circuit to motor I1 is broken, the'plunger 50 drops relatively quickly into place atv the bottom of the dash-pot, since the washer 53 is lifted off the openings 52 by the upward pressure of the liquid below. The dash-pot may be filled with oil or any other desirable fluid.

The solenoid 43 is connected for operation to Ithe terminal block 4|) by leads 54. In operation,

the leads from the mercury switch 36 are connected to an indicating or signalling device, shaft 21 is driven either from the mechanism which drives the belt conveyer or the mechanism which drives the pulverizer-feeder, or Stoker and the solenoidis actuated from the motor circuit of the motor which drives the belt-conveyer. Thus, the worm-wheel starts in a position in which the pin 38 or 48 is against the slider 45, and rotates until the weighing device operates and stops the driving `motor for the conveyer, and with it the shaft 21. At this time the current stops in the motor circuit, the solenoid 43 releases the armature 5| and the plunger 5I] drops to the bottom of the dash-pot 42. Now, if i the weighing device or weighing mechanism discharges the hopper full 4i aanname ofmiaterialetnezhonper-gatezcloses:anchthe-motoaw: 38amitheiowenalarm-.e- The.switch..=13,.-1.1owever,.

driving the be1t-conveyer is again started,-ezAtrithe.r; is sturnedebackwards in Ktheehinged frame. so

time; ofrstartingg,ithersolenoid-143iis energizedthe thatfzcontact.. is brokenwhennthe switch ,is-tilted. armature 5I: is liftedaand this. lifts thedash-potzl. andfmadelwhen'theswitch -is irr normal positioniassemblyl. :II 2 and. .with fit .1 thev endfroff I thewpiyotedf A,Thus` thetlower. alarm.; uni-tC can operate .on1y.,if shaftV 30;::so. that .the i wormewheeli. 29.' is,lifted..out.-, thenuppenalarm unit has not x operated, .because ofi'mesh withfthe wormr-28w SpringfMnthenn'e-f theoperation-,ofthe-upper alarm unitvwill break@ volveszpthe..wormewheele29: until ,the. pinr-38.-.or -l48vs; the-indicating ircuitof,the.1oweralarm.

strikes'ftheslideri. As .thefuidleakspast then; What is claimed is: y plunger". in ithe.\da,sh-:po.t,4 fthei-.worm-,wheele 9; is .1. -JOW 1. KApptmattusforY detectingnstoppages in the lowered into .contact-with theuworm 2&;f,aiml.,the-.A owmof.bulk-materialthrough a .feeden system. cycleibeginsagain: which -iincludes ,a driven. feedingedevice having..

If,.for.any,;reason, :there-is a -stoppagefof-maef v a .rotatingapart and a AL|atch..de1ivery device rre-4 terial. abovefthe i belt-conveyan, then the; conveyem ceiving.rinateriali#fromA said feeding ldevice,Y that Y 4 will operate for an abnormally ygr-,eatnnumber@01u51.comprisesa/.meansedriven.by the-*rotating part turns before the .'weighingfmechanisme-will:opere of the feeding device tofactuate ari-.alarm .signabY aten-e Therefore,theeworm-wheel 29v willbe turnedfq'.; afterf-a predetermined. angulardisplacement.of furtherfthan normal :and willstrike the upstand-.ay theirotating part which :is greater ,than .thenore i ngarm ontheihingedfra-me-35,l1ting-theswitchfmat-angularndisplacement: incident.- to supplying. 36;-fand1icausing.-,whatever'indicatoreis fused Ato hee.v 2o,..a batch .of bulk rmaterial to *thei deliver.y..device,1.=

operated. and ,means .operated Ybynsaid delivery` device, Yuporwz The-detai1sim?=oper2 11 rr-.oi` the signal1ng. .dethedeliveryV of .a "batch, toV reset themeans. driven. vices can-.beseenfpqrhaps even.moreclearly'froxnl by the rotating part of .the feeding` :device-andi. gure` 5 in whichfisshown a Circuit ydiagIar1f1.-0f,-V thus..in\ normal. operation preventtheactuation the-device From the .circuit between ,the starrteingofthe alarm, f switch `59 in boze` 58 ,and thefrnotonf-.power istaken 2.: Apparatus.. for l.detecting stoppages .in .,tlie..` diretlyjo operate in parallelfboth of. ,the resettinge` flow wot, bulk ,materialqthrough ,a ,-feeder. system/g solenoidsei and 431:1,.of4 itheupper or,scalealarmr` including-.a drivenieeding device having a rotaiav and the lowerior stoker. or,-pulverizerrfedenalarm..t ing-ipa anda batonweighingdevice vreceiving`r respectively-.,--4 SignaLCurrent is.V brpughtfthroughf-3omateria1from the said Yfeeding device and peri:- l leads 10/ to.. the-,umzier`V alarm,dev1cefwhereeitism 'odicauywdischarging .thegamwthae comprjsfys;.

connected in seriesto the mercury.TswitchfSIlto.f. meansdrjvenfbythe.rotating..fpart of, the feeding theindicating or.s1gnall1ng devicefll.. This .sigf dey/,16am actuan; ,an.alarmsignaLaftera prede nalline .device may `beganv electriclamnianelectermiried..angu1ar..disp1aeement i ofesaidmotating tric hom, a relay an electrically Operated'wh'stle' `Z55-part: which istgreater:y than.thenorma1. angular. orany other.y device thatgwllemit 0r displaytha displacement incident to feeding Lsuneienabuuew desired 4Signal 1111011 =1CJ112330I1--l IIIfChQIOWGT-fol'g material-:tdcause a dischargegon thefpartof the pulver-izer-feeder alarm; theconnections.. are -eX-`- Weighing :,Adevice'-landgmeans Operated :by said actly.the same. Thesignlal currentisbroughty wgighmg'devioejn the -dischargecyclefofits. op... thIGugh a l-"bilfof` leadSlzcolnectedfinfseles With- 40 erationdo interrupt. the .,.operationtoithe means..Y thelmeliculy' Switch dand thelsignalllflgdellic. dljvenibyK-the,rotatingigparboi Said feeding device;

'Haof-.the.\alarm. and.to,,reset thesanie so.asitoi-preventpactuationw From-.theoregoingitvv can..be.seen V.that .ifqa i. ofithe alarmri-rn normal operationJ stoppagegoccurs in.-or.above.-bunken I I, .bejltllrl 3.@Apparatusaoindetecting.,stoppagesin. the.,

wilhopelatefwthollt feedngfoal. to,.,h oppe.11- I8.v @mow-sof buik materialithrough v`a feeder system, ThU-S;rthenumbereofturns of-.mot0r.l1-wlllgleatlyf.' whichnincludesfa driven .-feedingtdevice having-,a a

exceed: the.-Il01`ma1 rlllmbBIQf UIIISIUGCSSaISL 130.. rotating part, and a, batch delivery devlcegceive. Supply@ predetermined nwelght-offaggrgarter i201., ingignaterial. from saidfeedngfdevice, that.,com, hopper.- |81` f- Motor;|lwill continue toirfun-.loecause-ly pnises;,-.an.alarm device, aneelectric circuit conthe-circuit,.theret0 liS bmkenv .Onlyzby .thertltngfu,lhtrolling operation. of. said alarm. deviceVa switchbeams I9 whichA will not occur unless,the'aggref in ,said circuit, means driven byitheirotatingpant. gate-is actually;reaching/@Opper luaThez-effect 0fthe,feeding,device, to` closesaidr switchafterea.

of, this will bertof continuato drive gean\.29.until predetermined angulaizdisplacement Aof .said ro the pini,thereonstrikes-1everw31 andoperates mer-a V tatmgpart greater. than ,the normalfangulandise cur-yiA switchv 36 to` give. an .alarmey Iffonftherother-r'omeplacementiincident `tot-supplying a vhatchof bulk hand -a @stoppagefwere to occur infchutezilthez material,..tothendelivery device. and; means ope,- aggregate .would pi1 e.up4 so.- that ,gatey 20- of .hoppen e erated--by saidzvldeliverydevice `upon` the rdelivery I8, i after; a discharge; .Operationgcould :not: close. ofga -batch offbulk .materialnto reset4v the vmeansM Thus, although the circuit-ftomotordllfhadmeen'; drivenefbvthetrotating part andthus ,in normal... broken by; the tiltingrof .beams I9-before-am alarm@@mygeneration prevent .theclosingfot the switch `in the hadabeen: given;- the, failureofv gate; I 8I- tofclosezfpreef alarm, .cir\::l.1it.,V ventsrthe.reestablishmentfiofgtheacircuitgto motor.4 4.1;Apparatus for detecting-.fy stoppages the I'Iiwhich in .turn .preventsestablishment ofta ,cire`t flow of bulk materialzrthroughfa .feedersystemw cuit.=to'either;.of.solenoids,i43.or.:l3au'.As-a cons which-iincludesev a driven'. feedingrrdevice khaving querice*7 the:.continuedn'otationfon ,theapalit: of-mesa rotating.=part: and .a batch delivery jdevicere pulverizer.-.feeder I 4 willresult intheperation ofc; ceiving-materia1..fromfsaid-feedingidevicep that.-

signalling; ,devicez f1 I a tto:` -indicateza :.stoplii.gerbe-z. comprises; a wheeldrivenv byithe rotatingipart vof tweenl hopper. .1I8. and :.pulverizer..feeder V:|41 fa saidiieeding device; a -pin on Vsaidi wheelfanelecf.

Whenit is :desired-i:to:zrendeiesthenstokerf orV i trical.switch,meansconnectedI toisaid switchandff pulverizer-feedenalarm;.inactive'npomactuationtz?oi'radapted:fto be contacted-by said fpin'upon there-.w of` `the upper or :scale alarm-'it is .onlynecessary tof: tation'lofsaid -whee1 to a predetermined extentsoY place` a .secondfimercury switch uponwthe i tiltablekf. 'astto lbias. said switch to-,circAiiteclosing` position-,fframe...:35,;of';.thevupper1alarm:zandrconnectmhise an-:e1ect-ric-.circuit,- controlled by ,said swtchfan-f mercury.l fswitchnwnich fisishowmat 13: in-:dottedalarmidevicedn saidf-circuitnandmeansf Operatedw lines'inLFgure-n seriesfwithfthmmercuryrswitchw;'Imbysaid deliveryfidevicuponthe delivery ofi-a batch of bulk material to reset said wheel to its starting position so as to prevent the closing'of the electricalcircuit controlling the alarm device unless the angular displacement of the rotating part of the feeding device is in excess of the angular displacement normal incident to supplying a batch to the delivery device.

5. Apparatus for detecting stoppages in the l iioW of bulk material through a feeder system which includes a driven feeding device having a rotating part, and a batch delivery device receiving material from said feeding device, that comprises; a worm, means for driving said worm from the rotating part of said feeding device, a worm wheel in mesh with said worm, a pin projecting from the face of said worm wheel," a

normal, open switch in the path of said pin adapted to be closed when the latter strikes it,

means normally biasing said pin to a starting position remote from the point kof contact with said switch, an alarm device, an electric circuit including said switch and said alarm device, means operated by said delivery device upon the delivery of a batch of bulk material for disengaging said Worm and worm wheel so that the latter will return to starting position, thus in normal operation preventing actuationof the alarm while if the angular displacementl of the rotating part of the` feeding device is greater than that normallyrequired in feeding a batch i of bulk material to the delivery devicev the worm including a driven feeding device having a rotating part, a batch delivery device fed by said feeding device and a second feeding device which receives material from the batch delivery device, saidfsecond feeding device also including a rotating part which apparatus comprises; means driven by the rotating part of the first feeding device to actuate `an alarm signal after a predetermined Vso angular displacement which is greater than the normal. angular displacement incident to the feeding of a batch to the batch delivery device, means driven by the rotating part of the second feeding device to actuate a second alarm system after a predetermined angular displacement which is greater than the normal angular displacement incident to the passagev of a batch of bulk material, and means operated by said vdelivery device upon the delivery of a batch to reset simultaneously both of the means driven by the rotating parts so as to prevent actuation of either alarm signal in normal operation.

8. Apparatus as set out in claim 7 which further comprises means to'render the second alarm device inoperative upon actuation of said first alarm device. v

9. Apparatus for detecting stoppages in the ow of bulk materials through avfeeder system including a driven feeding device', a batch delivery device receiving material from said feeding device, and a second feeding device which rereives material fromsad batch delivery device, said second device including a rotating part, which comprises; means driven by the rotating part of the second feeding device to actuate. an alarm signal after a predetermined angular displacement which is greater than the normal angular displacement incident to passage of a batch of bulk material, and means operated by said delivery device upon the delivery of a batch to reset the rotating part of said second feeding means and thus in normal operation prevent the actua tion of the alarm.

10. Apparatus for detecting stoppages in the flowl of bulk material through a feeder system which includes a bulk material measuring device and a driven feeding device, that comprises an 'alarm device, an electric circuitcontrolling operation of said alarm device, a switch in said circuit, means driven by the feeding device to close said switch after a predetermined displacement greater than the normal displacement incident to supplying a predetermined quantity of bulk material, and means operated by `said material measuring device upon the delivery of a predetermined quantity of bulk material to reset the means driven by the feeding device and thus in normal operation prevent the closing of the switch in the alarm circuit.

ARTHUR J. STOCK. NATHANIEL BREWER. 

